The feasibility of a thermal liquid-phase oxidation process has been tested to treat the organic content of industrial waste water derived from chemical industries. The effect of the operating parameters on COD removal including temperature, pressure, pH, and residence time was studied. The experiments were conducted in a stainless steel autoclave reactor and the maximum of 49.77% of COD removal was achieved after 120 min of reaction time at 2300C temperature and pH 7.9, indicating a significant improvement in degradability of organic effluent. An ideal pressure of 28 Kg/cm2 was observed for maximum COD removal of 43.18%. This liquid-phase oxidation technique shows the significant potential for the treatment of organic load of industrial wastewater.